Superconductivity in rubidium substituted Ba1-xRbxTi2Sb2O

We report on the synthesis and the physical properties of Ba1-xRbxTi2Sb2O (x < 0.4) by x-ray diffraction, SQUID magnetometery, resistivity and specific heat measurements. Upon hole doping by substituting Ba with Rb, we find superconductivity with a maximum Tc = 5.4 K. Simultaneously, the charge-density-wave (CDW) transition temperature is strongly reduced from T_CDW 55 K in the parent compound BaTi2Sb2O and seems to be suppressed for x > 0.2. The bulk character of the superconducting state for the optimally doped sample (x = 0.2) is confirmed by the occurrence of a well developed discontinuity in the specific heat at Tc, with \DeltaC/Tc = 22 mJ/mol K2, as well as a large Meissner-shielding fraction of approximately 40 %. The lower and the upper critical fields of the optimally doped sample (x = 0.2) are estimated to \mu0Hc1(0) = 3.8 mT and \mu0Hc2(0) = 2.3 T, respectively, indicating that these compounds are strongly type-II superconductors

Legitimate Protection or Tactful Abandonment: Can Recent California Legislation Sustain the San Francisco Bay Area\u27s Public Lands?

This Comment posits that parks that serve urban communities, such as the SF Bay Area state parks, are of particular importance due to the implications of open spaces for the health and well-being city dwellers. The consequences of legislation like AB 42 in urban environments are different from those in rural areas, and an awareness of these differences is necessary to draft effective legislation. For instance, parks serving urban areas frequently give rise to environmental justice concerns of wealth and poverty as reflected by extensive, well-appointed parks in more affluent communities compared to neighboring communities with less social and economic capital. Moreover, for those who live in urban centers or surrounding metropolitan areas, access to open space and nature is more restricted compared to those living in rural areas; parks, therefore, take on greater significance in urban contexts. For these reasons, this Comment will be focused on a discussion of parks in and around the SF Bay Area and how AB 42 might affect these parks. Part II provides an overview of the practical and theoretical context that led to AB 42 and the landscape into which the new law enters. This Part presents a brief survey of current thinking surrounding public land and its management, explores the particulars of AB 42, and provides a survey of SF Bay Area state park units and nonprofits that are likely to be affected by AB 42. Part III explores some of the possible pitfalls of AB 42. Part IV suggests ways in which the law might be improved and contends that partnerships with private nonprofits, on their own, will never be sufficient to sustain California’s state parks. Part V looks beyond AB 42 toward other solutions for California’s state park funding. Finally, the Conclusion urges the reader to closely monitor the successes and failures of AB 42 to better inform decisions to renew, repeal, or amend the law, and to reaffirm California’s commitment to an outstanding state parks system

Legitimate Protection or Tactful Abandonment: Can Recent California Legislation Sustain the San Francisco Bay Area\u27s Public Lands?

This Comment posits that parks that serve urban communities, such as the SF Bay Area state parks, are of particular importance due to the implications of open spaces for the health and well-being city dwellers. The consequences of legislation like AB 42 in urban environments are different from those in rural areas, and an awareness of these differences is necessary to draft effective legislation. For instance, parks serving urban areas frequently give rise to environmental justice concerns of wealth and poverty as reflected by extensive, well-appointed parks in more affluent communities compared to neighboring communities with less social and economic capital. Moreover, for those who live in urban centers or surrounding metropolitan areas, access to open space and nature is more restricted compared to those living in rural areas; parks, therefore, take on greater significance in urban contexts. For these reasons, this Comment will be focused on a discussion of parks in and around the SF Bay Area and how AB 42 might affect these parks. Part II provides an overview of the practical and theoretical context that led to AB 42 and the landscape into which the new law enters. This Part presents a brief survey of current thinking surrounding public land and its management, explores the particulars of AB 42, and provides a survey of SF Bay Area state park units and nonprofits that are likely to be affected by AB 42. Part III explores some of the possible pitfalls of AB 42. Part IV suggests ways in which the law might be improved and contends that partnerships with private nonprofits, on their own, will never be sufficient to sustain California’s state parks. Part V looks beyond AB 42 toward other solutions for California’s state park funding. Finally, the Conclusion urges the reader to closely monitor the successes and failures of AB 42 to better inform decisions to renew, repeal, or amend the law, and to reaffirm California’s commitment to an outstanding state parks system

Helen Nesper School Friendship Book

School friendship scrapbook including photos, programs, news clippings, letters, and other memorabilia. Please note that blank pages were not scanned in an effort to reduce the files size.https://digitalcommons.buffalostate.edu/scrapbooks/1011/thumbnail.jp

Graduate Recital:Paul Nesper, Tuba

Kemp Recital Hall Saturday Afternoon March 5, 2005 4:30p.m

Periodic Space Partitioners (PSP) and their relations to Crystal Chemistry

We are looking back on 30 years development of periodic space partitioners (PSP) and their relations to their periodic relatives, i.e. minimal surfaces (PMS), zero potential surfaces (P0PS), nodal surfaces (PNS), and exponential scale surfaces. Hans-Georg von Schnering and Sten Andersson have pioneered this field especially in terms of applications to crystal chemistry. This review relates the early attempts to approximate periodic minimal surfaces which established a systematic classification of all PSP in terms space group symmetry and consecutive applications in a variety of different fields. A consistent nomenclature is outlined and different methods for deriving PSP are described. Characteristic structure factor sets which solely define PNS by can be used to discriminate structure types of a given symmetry or even to determine complicated crystal structures. The concept of PSP relates space group symmetry, topology, and chemical bonding in an intriguing way and tessellations on PSP which can be generated in a straight forward way allow to predict new framework types. Through transformation of such continuous topological forms a new entry has been found for understanding and interpreting reconstructive phase transitions. Finally we indicate the importance of PSP models for soft matter scienc

Optical Coherence Tomographic Angiography Imaging in Age-Related Macular Degeneration.

Optical coherence tomographic angiography (OCTA) is emerging as a rapid, noninvasive imaging modality that can provide detailed structural and flow information on retinal and choroidal vasculature. This review contains an introduction of OCTA and summarizes the studies to date on OCTA imaging in age-related macular degeneration

Topological modeling of reconstructive phase transitions through periodic hyperbolic surfaces: the β-quartz to keatite type transition

The reconstructive transition β-quartz to keatite is evaluated by employing symmetry-adapted hyperbolic surfaces, i.e. periodic equi-surfaces (PES) as structural trial models. The PES descriptors reveal a transition model very close to the one discussed by Li et al. We can show that this model is associated with only a small shift of the principal structure factors in reciprocal space. We derive an intermediate structure halfway between quartz and keatite of P21 symmetry through symmetry considerations and group-subgroup relations. Atomic shifts are given. It is shown that topological modeling of reconstructive phase transitions by means of periodic hyperbolic surface descriptors is a valuable extension to MD methods in exploring possible transition coordinates. As the PES-method works strictly under symmetry control along group-subgroup relations it allows for a rationalization of both global structural changes and local chemical variations. The whole transition is described by means of only one significant set of structure factors for quartz and two sets for keatit